package top.wys.utils;
/**
 * Created by 郑明亮 on 2018/12/16 16:14.
 */

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.Base64;

import javax.crypto.Cipher;

/**
 * <ol>
 * 2018/12/16 16:14 <br>
 *
 * </ol>
 *
 * @author 郑明亮
 * @version 1.0
 */
public class RSACryptography {

    public static String data = "hello world";

    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub

        KeyPair keyPair = genKeyPair(1024);

        //获取公钥，并以base64格式打印出来
        PublicKey publicKey = keyPair.getPublic();
        System.out.println("公钥：" + new String(Base64Coder.encode(publicKey.getEncoded())));

        //获取私钥，并以base64格式打印出来
        PrivateKey privateKey = keyPair.getPrivate();
        System.out.println("私钥：" + new String(Base64Coder.encode(privateKey.getEncoded())));

        //公钥加密
        byte[] encryptedBytes = encrypt(data.getBytes(), publicKey);
        System.out.println("加密后：" + new String(encryptedBytes));

        //私钥解密
        byte[] decryptedBytes = decrypt(encryptedBytes, privateKey);
        System.out.println("解密后：" + new String(decryptedBytes));
    }

    //生成密钥对
    public static KeyPair genKeyPair(int keyLength) throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(1024);
        return keyPairGenerator.generateKeyPair();
    }

    //公钥加密
    public static byte[] encrypt(byte[] content, PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA"); //java默认"RSA"="RSA/ECB/PKCS1Padding"
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        return cipher.doFinal(content);
    }

    //私钥解密
    public static byte[] decrypt(byte[] content, PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        return cipher.doFinal(content);
    }

}
